The present invention relates to a process for scrubbing out sour gases, especially CO.sub.2, or CO.sub.2 in admixture with H.sub.2 S, from gaseous mixtures with an aqueous solution of a salt of an alkali metal and a weak inorganic acid, which solution is subjected to regeneration after absorption of the sour gases, and is subsequently reused.
Such a scrubbing process has been disclosed, for example, in German Pat. No. 1,084,425. In this patented process, sour gases, especially CO.sub.2, are converted with a potassium carbonate solution, during the scrubbing stage, into potassium bicarbonate; in the regenerating stage, the pressure is reduced, the reaction is reversed, and the carbon dioxide is withdrawn from the head of the regenerating column. To improve the absorption capacity of the scrubbing liquid, an activator (e.g. an ethanolamine) can be added to the potassium carbonate solution. Furthermore, it proved to be advantageous to also admix a vanadate to the scrubbing liquid to act as a corrosion inhibitor. This scrubbing method is distinguished by the ease of regeneration of the scrubbing medium. However, it has the disadvantage that substantial makeup circulating scrubbing liquid is required due to the gradual decrease in the absorption capacity of the scrubbing liquid. Other references relating to this process are, for example, US-PS 3,907,969.